Explosives of the type water-in-oil in the form of emulsions are well known and commercially available. Emulsion explosives were developed during the sixties and were made subject to patenting in the USA through U.S. Pat. Ser. No. 3,447,978. Many modifications in regard to constituents of both sensitizing and non-sensitizing character have been done since and in many cases have been made subject to patenting.
Explosives of the emulsion type contain in general an aqueous solution of an oxygen-releasing or oxidizing salt which is emulsified as a disperse phase in a continuous carbon-containing fuel phase. Moreover, the explosive often contains a uniformly distributed gaseous component.
Hitherto known explosives of the emulsion type almost always contain, in order to modify viscosity, waxes having a melting point within the range about 55.degree.-60.degree. C., having for their function to provide thickening of the continuous oil phase. Depending on the ratio between wax and oil the viscosity can be varied and changed. When the waxes solidify the emulsion adopts nature and flow properties which are a condition of the waxes. However, with solidification the waxes have a tendency to decrease in volume, and waxes of the paraffin type become brittle and easily breakable due to the structural change. With temperature changes and particularly at low temperatures the structure of the waxes change in an unfavourable direction. This in turn may be contributory cause to structure failure with concomittant exposure of the inner salt solution phase and crystallization. This phenomenon decreases the stability and detonational capability of the explosive.
Also at increased temperature emulsions of this type can be unstable for different reasons, but one of the causes being the tendency of the waxes to bring about release of the oil. Also in regard to the manufacture of the explosive its contents of waxes impose certain restrictions with regard to the procedure. Thus, for example the filling operation in packaging the explosive must take place quickly before the waxes solidify, and the packaging operation should preferably take place at a temperature lower than the solidification temperature of the waxes. It is conceivable to carry out the filling operation with cooled explosive mass, i.e. at a temperature lower than the solidification temperature of the waxes, but in addition to the fact that this is practically unsuitable this may also, considering the treatment of the mass is subjected to, effect the structure of the waxes and thereby negatively influence the stability of the product.
As a further disadvantage of the known technique there may be mentioned the fact that explosive compositions based on waxes are characterized by what is called "short" consistency which has for an effect that the explosive will be easily disintegrated when subjected to external stresses and particularly after longer storage periods.